Pneumatic boat



Dec. 3, 1940. .H. KRUPP 2,223,625

PNEUMATIC BOAT Filed April 1, 1939 nventr v Herman Kru D o Patenta& Dec. 3, 1940 UNITED STATES PATENT cme:

2123525 mumnc BOAT Herman Kruna, Seattle, wash. Application m-, 1939, Serial No. %5,337

bottom with a compartment between and entry ports or valves whereby this compartment fllls with water when theboat is placed therein, and whereby the water readily drains out when the boat is removed !rom the water. Another object is to provide a boat comprising several separate pontoons superimposed upon one another and flxedly connected together. The combination of the two foregolng objects provides a boat that is very steady in the water and one which will readily carry several people oi' 'average size even though the boat is comparatively small in size. Another resultant object or advantage in providing a pneumatic boat oi' small size and increased buoyancy is that it may be transported in an air plane or other small vehicle in its coi lapsed or folded condition and used as a life rait in an emergency.

In the drawing:

Figure 1 is a top plan view of the boat;

Fig. 2 is a bottom plan view of the same;

Fig. 3 'is a view in longitudinal vertical section taken on a broken line 3-3 ol Fig. 1: and

Fig. 4 isa view in transverse vertical section taken on a broken line 4-4 of Fig. 1.

Referring in detail to the drawing wherein like reference numerals indicate like parts in the several views, the numeral I designates a lower or bottom pontoon, and the numer-al 6 indicates an upper pontoon which is superimposed upon and fixedly connected to the lower pontoon. The upper pontoonj is provided with a pair of rowlooks 'i that are made oi' heavy or reentorced rubber and vulcanized or otherwise fixed' thereto, it being understood that both the upper and lower pontoon's are made of rubber or like m'aterial. A valve 8 serves as means for inflating or deflating the lower pontoon, and a corresponding valve 9 serves as means for inflating and deflating theupper pontoon. Two rings o and ,ii are respectively secured to the bow and the stern or the boat in any desirable manner. The central opening or space in which the occupants of the boat sit is designated by the numer-al 12 and extends downward through both pontoons to the double bottom which will now be described.

The double bottom is the most' important feature oi' this invention and consists of a lower bottom member !3 and an upper bottom member il. These two bottom members are vulcanized (CI. 9-11) i to thelower pontoon 5 thus making a water-tight connection therewith. They are disposed a short distance apart thus forming a compartment es therebetween. The lower bottom member !tis 'provided with a pair of water entry ports or 5 valves IS. Said ports are reenforced around their edges and are respectively located at the forward and rear ends of the lower bottom mem ber. The compartment IE readily fills with water entering through the ports s when the boat is placed in the water as shown in Fig. 3 of the drawing. When the boat is taken out of the water this compartment is readii emptied by the water drainng out through the ports s. The

boat is then defiated by means of the valves 8 15 and 9 and folded into compact form for storage or transportation.

Referring particularly to Fig. 3, when the compartment i5 is filled with water, the boat is thereby made unusually steady and the occupants may `step into the boat and stand up n its upper bottom member i 4 without tipping it to any marked extent. Water is caused to enter the double bottom compartment I5 through the ports s by persons in shifting their weight on the flexible bottom member N while moving. or walking around in the boat. Their shifting weight causes the flexible double bottom and its compartment to act as a pump in forcing the air out and drawing water in when the boat is first placed in the water.

When the air is pumped out it cannot reenter, and the weight of the water has a remarkable stabilizing' eflect in preventing the boat from tipping over. In

the use of a small boat that is substantially six or seven feet long and two and one-half feet wide, the weight of two average size persons causes it to sink down into the water about half its depth, or until the water level is even with the plane of joinder of the upper and lower pon- 40 port themselves in the water around the boat by holding onto its sides or to a grab line secured around its sides.

While I have described the double bottom as being secured to a boat consisting of several pontoons, it will, of course, be understood that this double bottom ma also be used on a boat consisting of only one pontoon. However, the double bottom distinctively cooperates with the pontoons oi a boat comprisin several pontoons in making the boat more steady and seaworthy,

and'in elminating the tendency to np over which has heretofore been so prevalent n this class of beats. This boat s adapted for use both 'm times of peace and in times of war.

I claim: a A pneumatic boat conslsting of pontoons connected together, a double bottom comp-tsins a lower and an upper flexible bottom member disber. t

HERMAN KRUPP. 

